The key problems concerning the physics of the solar atmosphere are still unsolved:

How is the Corona heated to more than a million degrees?

Where and how does the solar wind obtain its acceleration?

Which processes in the lower corona lead to the gigantic mass ejections observed?

To gain some insight into these problems is the goal of the
united ESA
- NASA mission
of the SOHO spacecraft.

The spacecraft is equiped with a number of new instruments for solar
observation, one of which is LASCO. This instrument monitors
the solar corona above the Sun's limb in a similar way as we perceive the
corona during a solar eclipse. It produces images of the corona in the
visible spectrum and with distance off the Sun's center ranging from
1.1 to 32 solar radii.

There is a close link between LASCO and another instrument,
EIT,
who share the same electronics unit through which the instruments
communicate with the spacecraft.
The spacecraft SOHO was launched on 2nd Dec 1995. The LASCO-C3 telescope
produced its first image on 29th Dec 1995, C2 and C1 on 26th Feb 1996 and
29th Jan 1996, respectively.